In a mixing bowl, combine fresh breadcrumbs with half & half and the egg. Allow this mixture to rest for 5 minutes to absorb the moisture.

Add in the grated onion, minced garlic, tomato paste, ground sirloin, hot Italian sausage, Worcestershire sauce, minced basil, and seasoning. Mix thoroughly until well combined, then shape the mixture into 1/4 cup meatballs.

Preheat your broiler and line a baking sheet with parchment paper. Arrange the shaped meatballs on the sheet, ensuring they’re spaced apart. Broil them for 10-12 minutes, turning halfway through, until they are browned and slightly crispy on the outside.

While meatballs are broiling, heat a large skillet over medium heat and drizzle in some olive oil. Add the diced yellow onion and sauté for about 2-3 minutes until softened. Stir in the minced garlic and crushed red pepper flakes.

Pour in the crushed tomatoes, tomato puree, and a sprinkle of sugar, letting it simmer gently.

Once the meatballs have broiled, carefully add them into the tomato sauce in the skillet. Stir gently to coat the meatballs in the sauce and cover with a lid. Reduce heat to low and simmer for approximately 45 minutes.

Fill a large pot with salted water and bring to a boil. Cook the spaghetti according to package instructions until al dente, usually around 8-10 minutes. Drain the spaghetti.

To plate, toss the cooked spaghetti with the rich tomato sauce. Serve the meatballs on top, garnished with torn fresh basil and grated Parmesan cheese.